Photographic printing



p 39301 J. EGGERT ET AL PHOTOGRAPHIC PRINTING Filed Jan. 6, 1954 2Sheets-Sheet l v In venfors Afforne Sept 22 E93& J. EGGEJRT ET ALPHOTOGRAPHIC PRINTING 2 Sheets-Sheet 2 Filed Jan. 6, 1934 Inventors.-

By 6H0? 5 Patented Sept. 22, 1936 UNITED STATES PHOTOGRAPHIC PRINTINGJohn Eggert, Leipzig-Gohlis, and Gcrd Heymer,

Wolien Kreis Bitterield,

Germany, assignors to I. G. Farbenindustrie AktiengesellschaiFrankfort-on-the-Main,

Germany Application January 6, 1934, Serial No. 705,604 In GermanyJanuary 14, 1933 4 Claims. (01. 95-75) Our present invention relates tophotographic printing and more particularly to printing lenticularfilms.

One of its objects is to provide an improved process of this kind.Another object is an apparatus for carrying out our improved process.Further objects will be seen from the detailed specification. followinghereafter. Reference is made to the accompanying drawings in whichFigure 1 shows diagrammatically an apparatus according to thisinvention,

Fig. 2 shows a conventional view of an apparatus for printing accordingto our invention,

Fig. 3 shows a section of Fig. 2 on the lines Fig. 4 showsdiagrammatically a plan view of another arrangement for printingaccording to our invention, and

Fig. 5 shows an illuminating device which may be used instead of thelinolite lamp shown in Figs. 2 and 3.

In printing color-record images from a lenticular film on to alight-sensitive lenticular film by contact, the original film, as it iscalled, and the film to be printed on are placed with their embossedsides facing each other, and the exposure is through the emulsion layerof the original film. When exposure is made with direct light, as isnecessary in printing lenticular films, the known phenomena producingmoire efiects occur. In order to eliminate these moir efiects numerousexpedients have been proposed; for instance, optical elements have beenplaced between the source of light and the film, or each individualpicture has been displaced in printing by the breadth of one lenticularelement with relation to the film to be printed on.

According to this invention the formation of moir efiects in contactprinting is avoided by the mere application of mechanical means, withoutdisplacing the lenticular embossings of the original with relation tothe film to be printed on. For this purpose the printing film isarranged in contact with the original with the embossings facing eachother and is exposed through the original to a source of light limitedboth n a direction parallel to the lenticular elements and ina.direction transversely thereof. This source of light is reciprocatedwhile printing each individual picture in such a manner that, in eitherend position the center of the source of light, the border of the gateaperture and the center of that plane which, during exposure of theoriginal film, is occupied by the virtual image of the exposure filter,lie on a. straight line.

In the accompanying drawings, Fig. 1 represents diagrammatically anarrangement in ac- 60 cordanoe with the present invention. In thisfigure of the drawings H is the original film and I2 is the printingfilm having thin embossed sides in contact. I9 is the virtual filterimage of the exposure filter, through which the original film II hasbeen exposed. I8 is the center of the virtual image of the exposurefilter i9. The source of light consists of a slotted diaphragm 28, apiece of ground glass placed behind the slot and an incandescent lamp 26behind the ground glass, or it may consist of a simple incandescentthread. In the direction perpendicularly to that of the cylindricallenses this source of light has at least such an extension that itsubtends the same angle as is subtended by the virtual image of theexposure filter [9 when viewed from the film. Near the gate 13 is placeda slotted diaphragm I! which in its longitudinal direction extendsparallel to the direction of the lenticular elements and in thisdirection leaves the aperture uncovered throughout its extension. 20

The breadth of the slot has an influence on the produced picture. It ispossible to obtain pictures with a slot having a breadth equal to 25 percent or more of the breadth of the film, however, good results will beobtained with a slot having a breadth equal up to about 5 per cent ofthe breadth of the film. During the exposure of each individual picture,both the source of light consisting of the incandescent lamp 28, the

ground glass plate 25, and the diaphragm 28, and the slotted diaphragmI! make one reciprocatory movement between the two end positions whichare indicated by giving the numerals of corresponding parts in one ofthese positions an apostrophe. At any point of the movement the centerof the unmasked part of the ground glass plate 25, the center of theslot I1 and the point I8 must be on a straight line. For this purposethe slot and the source of light are mounted on a common support M-which moves about l8 as a pivot.

Instead of the source of light shown in Fig. 1 there may also be used astationary source of light which in the direction parallel to that ofthe lenticular elements has only a small extension, for instance, bymasking the source of light by a slotted diaphragm. In front of thesourceof light thus limited another slotted diaphragm is arrangedparallel to the lenticular elements which is moved to and fro. The endpositions of this slotted diaphragm are the same as the end positions ofthe source of light as shown in Fig. 1.

In order to avoid moving the slot and the source of light, there may besubstituted for this latter a number of individual lamps which are soconnected that a definite number of them may be switched on insuccession in a well-known manner. The zndivi al lamps must correspondas fill Q aosaoee to width and position with the source of light whichthey replace.

an arrangement for printing according to this invention will be moreclearly seen from Figs. 2 and 3. In these figures the originallenticular film ii and the printing film ii are passed in contactthrough the gate it. Near the gate there is placed the diaphragm 39provided with a slot ii. In front of the diaphragm there is arranged thelinolite lamp id. This linolite lamp has such a breadth that it subtendsat least the same angle when viewed from the original as is subtended bythe virtual image of the exposure filter with relation to the original.The lever M is rotatable about a pivot it. This pivot lies at the pointwhich would be occupied by the optical center of the virtual image ofthe exposure filter with relation to the original. The lever it carriesthe mount 05 of the linolite lamp i6 and by means of the arm 2?9th ediaphragm I'l. During each printing step the lever id is so rotated thatthe diap i7] passes over-the whole breadth of the film.

Instead of using a linolite lamp there may also be used an illuminatingdevice as illustrated in Fig. i. In this figure, 25 is a source of lightwhich projects light on the ground glass plate 25 covered on the sideremote from the source of light by the diaphragm 28. This diaphragm isprovided with a slot 211 which in the direction perpendicular .to thelenticular elements has a breadth which fulfils the above conditionstated with regard to the breadth of the linolite lamp and which in thedirection parallel to the lenticular elements has as small a breadth aspossible.

Fig. 5 shows another arrangement for printing according to thisinvention. Through the picture gate is there are passed the originallenticular film i i and the lenticular printing film I2 in contact. Thelever id which is rotatable about a pivot is placed at the point whichwould be occupied by the center of the exposure filter is (shown tor thesake of clarity in dotted lines) with relation to the original, carriesthe slotted diaphra ill arranged near the gate 53. At 23 there arearranged a series of individual lamps on an are which has the pivot 18as centre or there is arranged a continuous incandescent filamentforming such an arc. From this are branch 0d a plurality of contacts..At its end remote from.

the pivot is, the lever as carries a herd M which at both ends isprovided with contacts 26. These contacts 20 are connected with a sourceof electric energy and spaced apart so that they subtend the same anglewhen viewed from the original as is subtended by the exposure filter as(shown for the sake of clarity in dotted lines). Thus, when rotating thelever there will always be switched on light in the required breadth.

What we claim is: a

1. In an apparatus for printing lenticular films in combination a gateprovided with an aperture, a lenticular film'bearing an original and alight- -sensitive lenticular film in contact with their lenticularelements facing each other, in said that it is seen under the same angleas'thevirtual image of the taking filter when viewed from the film, aslotted diaphragm arranged near said gate, the breadth oi the s1 t beingat most equal to 25 per cent of the breadth of the films, and means fordiaphragm arranged such that the centers of said source of light and ofsaid slotted diaphragm form a straight line, on an are having as itscenterthe point which would be occupied by the center of the exposurefilter with relation to the original.

2. In an apparatus for printing lenticular films in combination a gateprovided with an aperture, a lenticular film bearing an original and alightsensitive lenticular film in contact with their lenticular elementsfacing each other in said gate a source of light arranged on the side ofthe original comprising a disk of ground glass illuminated by anincandescent lamp arranged on the side of the original and limited bydiaphragms so'that it has at least such a breadth that it is seen underthe same angle as the virtual image of the taking filter when viewedfrom the film and only a, small extension as regards its length, aslotted diaphragm arranged near said gate the breadth of the slot beingat most equal to 25 per cent of the breadth of the films and means forreciprocating said source of light and said slotted diaphragm arrangedsuch that the centers reciprocating said source of light and saidslotted of said source of light and of said slotted diaphragm form astraight line, on an are havin as its center the point which would beoccupied by the center of the exposure filter with relation to theoriginal.

3. In an apparatus for printing lenticular films in combination a gateprovided with an aperture, a lenticular film bearing an original and alightsensitive lenticular film in contact with their lenticular elementsfacing each other, in said gate, a slot-shaped source of light arrangedon the side of the original extendingin the direction parallel to thelenticular elements and diaphragm before said slot-shaped source oflight cutting out a portion of at least such a breadth that the latteris seen under the same angle as the virtual image of the tamng filterwhen viewed from the film, a slotted diaphragm near said gate thebreadth of the slot being at most equal to per cent of the breadth ofthe films, and means' for reciprocating said diaphragm before saidslotshaped source of light and said slotted diaphragm arranged such thatthe centers of both diaphragms form a straight line, on an are having asits center the point which would be occupiedby the center of the.exposure filter with relation to the original. s

4. In an apparatus for printing lenticular in combination a gateprovided with an aperture, a lenticular film V sensitive lenticular filmin contactwith their sources of light which can be switched on one afterthe other having at least such a breadth that they are seen under thesame angleas the virtual image of the filter when viewed from the film,a. slotted diaphragm near said gate the breadth of the slot being atmost equal to 25" per cent of the breadth of the films", and-means forreciprocating said diaphragm, on hav ing its center the point which.would be cccupied by the center of the exposure filter. JOHN EGGERT. Gmhm-i-

